Gas cooling process and apparatus

ABSTRACT

A cyclic gas cooling apparatus and process comprising a thermal compressor and thermal regenerative means in communication with a pressure regenerative means which produces, by a combination of thermal compression and thermal regeneration and pressure regeneration of the working gas introduced into and contained in said thermal compressor and thermal regenerative means, a decrease in the temperature of the gas. Such gas is then introduced into a surrounding confined space or brought into contact with an object at a higher temperature where its low temperature will result in a cooling effect.

United States Patent Mokadam 1 Sept. 12, 1972 [54] GAS COOLING PROCESS AND APPARATUS [72] Inventor:

[73] Assignee: Institute of Gas Technology,

Chicago, Ill.

[22] Filed: Jan. 5, 1971 [21] Appl. No.: 104,008

52 US. Cl. ..62/6, 62/86, 62/467 51 1m. 01 ..F25b 9/00 58 Field 61 Search ..62/6, 86, 467

[56] References Cited UNITED STATES PATENTS 1,169,308 1/1916 Vuia.. ..62/6 2,157,229 5/1939 Bush ..62/6

Raghunath G. Mokadam, Chicago, Ill.

Bush ..62/6 2,567,454 Taconis ..62/6

Primary ExaminerWilliam J. Wye Attorney-Alexander and Speckman [5 7] ABSTRACT A cyclic gas cooling apparatus and process comprising a thermal compressor and thermal regenerative means in communication with a pressure regenerative means which produces, by a combination of thermal com pression and thermal regeneration and pressure regeneration of the working gas introduced into and contained in said thermal compressor and thermal regenerative means, a decrease in the temperature of the gas. Such gas is then introduced into a surrounding confined space or brought into contact with an object at a higher temperature where its low temperature will result in a cooling effect.

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sum 2 OF 2 will \llll PRESSURE REGENERATOR 1.\'\ 1 RAGHUNATH G. MOKADAM "WPRESSURE REGENERAT R 4| 17a 1 7 l 174 I .1 I

. J ATT YS 1 -GAS COOLING PROCESS AND APPARATUS Gas cooling devices and methods, more popularly known as air conditioning systems when the gas used is air, such as motor driven compressor systems and absorption refrigeration systems have depended heavily on harnessing the energy change which occurs upon the change of phase from liquid to gas of a refrigerant material. Therefore, it has been necessary to have a refrigerant which is condensible to a liquid within the operating range of temperatures and pressures of the system. It has also been the practice to have a vapor compressor capable of condensing the vapor from the evaporator to higher pressure so that heat taken up by the refrigerant may be rejected from the system at a higher temperature. Thus, not only are gas cooling systems of the prior art limited by the materials which may serve as refrigerants, but they are also limited by the fact that vapor compressors are usually mechanical compressors which are large in size, relatively inefficient, and high in noise level. Also in many prior art devices and methods problems arise relating to the large number of moving parts and valves which are subject to frequent breakdown for a variety of reasons. In addition, some parts, such as the throttling valve which is between the condenser and the evaporator, are extremely inefficient in their operation.

My invention overcomes many of the disadvantages of prior art because my new apparatus and process does not rely upon any change of phase in either a working fluid or a cooling fluid to produce its cooling effect. It, therefore, requires no evaporators or vapor compressors, ejectors, jet pumps, or nozzle type cooling devices. My invention provides a cooling apparatus small in size, efficient, with a low noise level, and, because the gas itself functions as the working fluid which is cooled, the cost of operation is low, yet the simplicity of operation is high. Since in room air conditioning, air is used as the working fluid, no special means or seals are therefore necessary in the apparatus to avoid loss of the refrigerant" to the atmosphere as is the case when expensive and/or dangerous fluids are used.

Furthermore, the only necessary moving parts in the apparatus of my invention are valves and an oscillating paddle. The small number of moving or mechanical parts results in greater efficiency and less likelihood of mechanical breakdown and provides an apparatus which can be more effectively hermeticallysealed.

My invention comprises a novel and efficient combination of thermal compression and thermal regeneration with pressure regeneration, providing a highly efficient cyclic gas cooling process and apparatus having minimum energy input requirements. I achieve high efficiency, low cost cooling by a combination of a unit which I call the thermal compressor and thermal regenerative means (CORE) and the pressure regenerator process and apparatus more fully described in the co-pending application Fluid Pressure Regenerator and Process by Raghunath G. Mokadam and Andrew A. Fejer, filed concurrently herewith Ser. No. 104,009, filed Jan. 5, 1971, which combination produces the novel result of directly cooling gas channeled through the system.

The thermal compressor and thermal regenerative means comprises an insulated vessel for confining gas,

valve means in the vessel for regulating the flow of gas into and out of the vessel, a paddle means for displacing gas within the vessel, means in the vessel for heating the gas, means in the vessel for cooling the gas, a heat regenerative means in the vessel which is between the heating means and the cooling means, a cooling volume in the vessel which contains or is between the cooling means, and a heating volume in the vessel which is between the heating means and the cooling volume or a cooling means.

The Pressure Regenerator Apparatus and Process comprises one or more valve means each of which in succession sequentially transfers into a series of storage vessels, each being isolated from the other and from' the alternating gas system by said valve means, successive fractional portions of the gas exhausted from the alternating gas system, during transition from the high pressure cycle to the low pressure cycle. Each such storage vessel has a different final pressure sequentially becomdescribed by a thermal compressor and thermal regenerative unit (CORE) at the initial stage of the cycle containing gas at maximum pressure and maximum temperature. The gas is then allowed to expand into the pressure regenerator which causes the pressure and temperature of the gas in the CORE to be reduced. Since a portion of the gas in the CORE was originally at some untreated temperature, called ambient, which it was desired to reduce to a lower temperature, this portion may now be released to the confined space to be cooled at a temperature lower than the ambient temperature, or may be used to receive heat from higher temperature objects, thus causing a cooling effect. The released or used gas is replaced in the CORE by new gas at ambient or untreated temperature. The portion of gas stored in the pressure regenerator is then recovered into the CORE while the cooling means is operating, thus effecting isothermal compression of gas 7 in the cooling volume of the CORE and an increase in the pressure of the gas in the CORE. The pressure in the CORE is then further increased by a recovery of the heat contained in the heat regenerative element of the CORE and heat received from the heating means in the CORE. This results in the gas now contained in the CORE being returned to the same temperature and pressure as the gas originally present at the beginning of the cycle. Thus, the cyclic gas cooling process and apparatus has produced, by means of thermal compression, thermal regeneration and pressure regeneration, a quantity of gas which, when introduced into a surrounding confined space or used in contact with an object at high temperature, effects cooling. At this point,

my apparatus is in condition to proceed through another similar cycle and produce another cooling mass of gas.

It is an object of my invention to provide a gas cooling apparatus using thermal compression, thermal regeneration and pressure regeneration.

It is a further object of my invention to provide a gas cooling system using gas as the working fluid and cooling such gas directly, thus avoiding the necessity of using a refrigerant which must be condensible to a liquid within the operating range of temperatures and pressures of the system.

It is another object of my invention to provide an efficient gas cycle gas cooling process and apparatus having a small number of moving parts subject to mechanical breakdown.

It is a further object of my invention to provide a cooling apparatus and process eliminating the inefficient throttling valve used in the prior art cooling devices. I

It is still another object of my invention to provide a gas cycle gas cooling process and apparatus which requires no vapor compressor, evaporator, ejector, jet pump, or nozzle type device.

It is a further object of my invention to provide a gas cycle gas cooling process and apparatus using an activated or deactivated cooling means to obtain isothermal compression of gas in the cooling volume.

These and other important objects of my invention will become apparent from the following description and from the drawings showing preferred embodiments wherein:

FIG. 1 is a schematic drawing of my gas cycle gas cooling apparatus having a single thermal compressor and thermal regenerative means.

FIGS. 2 through 6 inclusive schematically illustrate the cyclic operation of my gas cooling process.

FIG. 7 is a schematic drawing of my gas cycle gas cooling apparatus having a single recovery and charging valve means.

FIG. 8 is a schematic drawing of my gas cycle gas cooling apparatus having multiple thermal compressor and thermal regenerative means.

FIG. 9 is a schematic drawing of my gascycle gas cooling apparatus having two separated cooling means within the thermal compressor and thermal regenerative means and having a single recovery and charging valve means.

Referring specifically to FIG. 1, a preferred embodiment of my gas cycle gas cooling apparatus comprises a I thermal compressor and thermal regenerative means 10 comprising vessel 11, a cooling means 12 within the vessel 11, a heater means 13 within the vessel 11, a heat regenerative means 14 within the vessel 11 and between the cooling means 12 and the heater means 13, and a paddle means 15 oscillating on a shaft 16 which is disposed through vessel 11 and is retained in suitable rotatable relationship by bearing means (not shown) at either end of the shaft 16. Shaft 16 penetrates vessel 11 in gas-tight relationship and is connected outside of the vessel 11 through suitable linkage means to a small power source (not shown) which causes the shaft 16 and the attached hub 17 and paddle means 15 to oscillate. The insulating hub 17 is secured to shaft 16 and carries the paddle means 15 constructed of suitable supported thermal insulating material extending to and congruent with the inside surface of vessel 11. Paddle means 15 oscillates between positions a and b as shown in FIG. 1 to be about In the embodiment shown in FIG. 1, the cooling volume 50, within the vessel 11, contains the cooling means 12, and is the volume defined by the inside walls of the vessel 11 and the facing sides of the paddle means 15 in a position a and the heat regenerative means 14. Heating volume 51, within the vessel 11, is the volume defined by the inside walls of the vessel 1 1, and the facing sides of the paddle means 15 in a position a" and heating means 13.

The cooling volume 50 within vessel 11 of thermal compressor and thermal regenerative means 10 is in communication with the outside gas if the system is open or the recycled gas if the system is closed, through inlet valve means 20 on conduit means 22 and in communication with the confined space to be cooled or a heat exchanger in the case of a closed system through outlet valve means 21 on conduit means 23. The vessel 11 is in communication with a multiple cell pressure regenerative means 30 through charging valve means 40 and recovery valve means 41'.

The cooling of a quantity of gas and its introduction into a confined space such as a room is accomplished through cyclic operation of the apparatus of my invention as shown in FIGS. 2 through 6 inclusive. In FIG. 2 the paddle means 15 is initially at point a and inlet valve means 20, outlet valve means 21, charging valve means 40 and recovery valve means 41 are closed. The

temperature of the gas contained in cooling volume 50 is at an ambient temperature T The gas contained in heating volume 51 is at a high temperature T which is greater than T The pressure throughout the entire vessel 1 l is constant at a high pressure P,.

With the gas contained in the vessel 11, at the temperatures T and T and a pressure P the charging valve means 40 is opened when P, is attained in vessel 11 and paddle means 15 is at point a" as shown in FIG. 3 and the gas in cooling volume 50 and heating volume 51 is allowed to expand through conduit means 42 sequentially through vales 31, 32, 33, 34, and 35 into the successive storage vessels 71, 72, 73, 74, and 75, of the multiplestorage vessel pressure regenerative means 30 by the process more fully described in copending application Pressure Regenerator Apparatus and Process mentioned above. In operation, the first storage means is opened to communication with the alternating fluid system and is initially at a lower pressure than the alternating fluid system. When the fluid pressure level in the first storage means is less than or equal to the fluid pressure level in the alternating fluid system, the pressurized fluid or a first portion thereof is isolated and stored in the first storage means. The second and any further succeeding portions of this pressurized fluid remaining in the fluid system may then be transferred successively, by a second conduit means through a second valve means to a second storage means, having a pressure level lower than the reduced pressure level of the alternating fluid system, thereby raising the pressure level in the second storage means to a point below or equal to the fluid pressure level in the fluid system, after which time the second valve means is closed. The next succeeding portion of the pressurized fluid remaining in the fluid system by a next succeeding conduit means to the next succeeding storage means having a pressure level lower than the further reduced pressure level of the alternating fluid system thereby raising the pressure level in the next succeeding storage means to a point below or equal to the pressure in the fluid system. The sequential transferring is repeated in succession until the desired amount of pressurized fluid transferred from the fluid system through succeeding valve means to isolated succeeding storage means has been stored. While this expansion is taking place the cooling means 12 remains inactive. The expansion of gas into the pressure regenerative means 30 reduces the pressure level in vessel 11 to a pressure P 'which may be somewhat above the ambient pressure. The reduction in the pressure level of the gas in the vessel 11 causes the temperature of the gas contained in cooling volume 50 to fall to a temperature T Since the cooling means 12 is inactive during this expansion, the fall in the temperature of the gas contained within the cooling volume 50 will be essentially adiabatic and isentropic and not the result of any thermal input or exchange. If the cooling means 12 uses a moving coolant fluid and fluid remaining in the cooling means 12 after its prior deactivation has sufficient heat capacity, T will not be low but such coolant fluid will be chilled and may be used in addition to the low temperature gas in cooling volume 50 for cooling of the ambient gas or any other desired cooling effect.

The charging valve means 40 is now closed as shown in FIG. 4 and outlet valve means 21 is opened. The quantity of gas contained in cooling volume 50 is introduced into the confined space to be cooled through outlet valve means 21 with the aid of a suction means 60 such as a fan or a blower. Since the temperature T, of this gas is lower than the temperature of the gas of the confined space to be cooled, into which it is introduced, this gas produces the desired cooling effect when it is introduced. The quantity of gas introduced into the confined space to be cooled is in turn replaced within cooling volume 50 by outside gas through inlet valve means 20 which is opened after the pressure levels within and without vessel 11 have become equal following the opening of valve means 21. This outside gas, at a temperature T which is higherthan T and a pressure P,,, then fills cooling volume 50. The outlet valve means 21 is closed when the temperature in cooling volume 50 equals the temperature of the space to be cooled and the cooling means 12 is activated to maintain the temperature of the air contained in cooling volume 50 at a constant temperature T The paddle means is then moved from position a to position b, as shown in FIG. 5. A major portion of the heat transferred to gas contained in heating volume 51 by heating means 13 during oscillation of the paddle means 15 is stored in heat regenerative means 14. The pressure in the vessel 11 during the oscillation of paddle means 15 remains constant at P because inlet valve means is open. The temperature in any section of the vessel is not altered by the paddle movement.

Referring to FIG. 6, inlet valve means 20 is now closed and recovery valve means 41 is opened allowing recovery of the pressurized gas stored in the multiple storage vessel pressure regenerative means 30 in reverse sequence to storage through conduit means 43. This return is initiated at the beginning of the transition of the system from the low to high pressure cycle by transferring the portion of the pressurized fluid from the storage means having the lowest pressure to the fluid system through the valve means in communication therewith. The emptied storage means is again isolated, and proceeding in like manner, the portion of the pressurized fluid contained in the number of succeeding storage means having increasingly higher final pressure levels, is successively transferred to the fluid system, thus providing regeneration of fluid pressure in an alternating high and low pressure system. This sequentialrecovery of pressurized gas increases the pressure level of the gas contained in vessel 11 to a pressure P which is greater than P but less than P However, the temperature of the gas in cooling volume 50 is maintained at T because of the action of cooling 'means 12, and therefore the compression of gas in cooling volume 50, which results from the recovery of the pressurized gas stored in pressure regenerative means 30, is accomplished isothermally.

The recovery valve means 41 is then closed. The paddle means 15 is now moved in reverse oscillation from position b back to position a, as shown in FIG. 1. This oscillation causes a portion of gas comparable in volume to that contained between position a and position b of vessel 11 to be moved through the cooling volume 50, heat regenerative means 14 and past heating means 13 into heating space 51. This gas, which has been brought to a temperature T by the cooling means 12 within cooling volume 50 receives heat from the heat regenerative means 14, as it passes through said heat regenerative means 14, which increases its temperature. The temperature of this portion of gas further increases as it moves past the heating means 13. The net effect, then, of moving the paddle means 15 to position a is to raise the temperature of a portion of the gas contained in vessel 11 as this portion moves through the cooling volume 50, heat regenerative means 14 and past heating means 13 into the heating volume 51, and to thereby raise the pressure in the vessel 11 from P, to 1 Cooling means 12 is deactivated and the gas contained in cooling volume 50 is now at a pressure P, and a temperature of T while the gas contained in heating space 51 is at a pressure P, and a temperature T which is higher than T,,,. Thus, the vessel 11 now contains gas at the same temperatures and pressure that it did originally, the cycle is complete, and conditions are set to begin a new gas cooling cycle.

It is obvious from the description of the preferred embodiment shown in FIG. 1 that the charging valve means 40 and the recovery valve means 41 could be a single valve means and that the charging of the pressure regenerative means 30 and the recovery from the pressure regenerative means 30 could both take place from one point only on the vessel 11 of the thermal compressor and thermal regenerative means 10. Such an embodiment is shown in FIG. 7.

There may, however, be many points on the vessel 11 from which charging and/or recovery to the pressure regenerative means 30 could be effected. In such a case a multiple conduit manifold would replace the conduit means going to valve means 40 and 41. Also, in such a case a single valve means 40/41 could be used. Though gas may be transferred from or recovered to the vessel 11 at several points located about the vessel 11, it is preferred that these points be located in such a manner thatno gas in the vessel moves into and through the cooling volume 50 during charging; that gas from the heating volume 51 moves past the heating means 13, during charging; and, that pressurized gas enters the cooling volume 50 and the heating volume 51 through the cooling means 12 during recovery.

.In the preferred embodiment of my invention shown in FIG. 8, the cooling process and cycle is the same as that described with regard to FIGS. 2 through 6 inclusive. The significant difference is that FIG. 8 describes the apparatus of FIG.- 1 as having a multiplicity of thermal compressor and thermal regenerative means 70, 71, 72 and 73 in communication with a multiple storage vessel pressure regenerative means 30 through a single charging valve means 40 and recovery valve means 41 on conduit means 42. These thermal compressor and thermal regenerative means 70, 71, 72 and 73 are also in communication with the confined space to be cooled through identical inlet valve means 20 on conduit means 22 and identical outlet valve means 21 on conduit means 23. The advantage of this embodiment is that it permits cooling of a larger quantity of gas in each cycle than the embodiment described in FIG. 1.

The thermal compressor and thermal regenerative (CORE) means 10 described above is unique in that the pressure contained in the volume of the unit called the cooling volume 50 fluctuates during the gas cycle. The vessel 11 of the CORE means 10, also may have more than one exit port and more than one entry port for the gas. In addition, the CORE means 10 may use an intermittent type cooling means 12 which is active during the rise of pressure of the gas in the cooling volume 50 and inactive during the fall of pressure of the gas in this cooling volume 50. Moreover, the pressure fall in the vessel 10 and cooling of the gas in the cooling volume 50 of the CORE means 10 is due to adiabatic expansion of the gas into the pressure regenerative means 30 rather than to thermal input or exchange. Furthermore, the pressure rise in the CORE means 10 is only partly, not entirely, due to thermal input or exchange, a substantial part being caused by pressure regeneration. Finally, in the CORE means 10, the paddle means 15 acts to move the gas within the CORE means 10 and not to aid in expelling the gas from the CORE means 10.

The cooling means 12 may be an exchanger carrying a moving liquid gas coolant such as cold tap water or air circulating through a conduit means in cooling volume 50, in which case it should be possible to stop or divert the fluid flow at the appropriate times. Said cooling means, however, may be a heat pipe capable of intermittent operation. Such a heat pipe may be a closed vessel containing a condensible liquid and having one end inside the vessel 11 within cooling volume 50 and the other end outside the vessel 1 1. The portion inside acts as a boiler, evaporating and removing heat from the cooling volume 50, while the outside portion condenses the vapor and rejects the heat obtained inside the vessel ll. The cooled liquid then recycles itself.

It is also obvious that the cooling means 12 may consist of two annularly shaped separate elements on either side of cooling volume 50, one adjacent to the heat regenerative means 14 and one adjacent to the paddle means 15 at position a as shown in FIG. 9. Cooling means 12 in this configuration would operate continuously thereby cooling gas as it enters or exits cooling volume 50 rather than cooling it as it passes through or remains confined in the cooling volume 50.

Heating means 13 is preferably a tube bundle heater and may be supplied with heat obtained by combustion of natural fuels such as gas, fired from within, or alternatively electrically heated, or may use a heat transfer fluid by introduction and exit. increased heat transfer within heating means 13 may be achieved by employing extended surfaces attached to the tubes and using radiation shields of wire cloth surrounding heater tubes which additionally prevent radiation from unduly heating the adjacent areas.-

There should be ample free space in the cooling volume 50 and in the heating volume 51, but the dead space in the heating means 13 and in the thermal regenerative means 14, should be as small as possible to allow the maximum amount of gas to be cooled and released per cycle. It is important that during storage of pressure in the pressure regenerative means 30, as little gas as possible flow-through the cooling volume 50 from any other area of the vessel 11. In addition, during recovery of the pressurized gas in an embodiment of the gas cycle gas cooling apparatus having dual, continuous cooling means 12 as shown in FIG. 9, it is necessary that the gas entering the vessel 11 flow through one of these cooling means 12 and cooling volume 50 before finally residing in heating volume 51. These conditions are necessary to insure that expansion of the gas is adiabatic and compression of the gas is approximately isothermal. Satisfaction of these conditions can be obtained as long as charging of the pressure regenerative means 30 and recovery from the pressure regenerative means 30 occur at the points on the vessel shown in FIG. 1. It is also possible to satisfy these conditions by permitting both charging and recovery to occur from a point in or between the heat regenerative means 14 and the cooling volume 50 as shown in FIG. 7. Preferably both charging and recovery should occur at the interface of heat regenerative means 14 and cooling volume 50, thereby preventing contamination of the cooling volume with hot gases and utilizing the full width of the temperature gradient of the heat regenerative means for cooling the hot gases.

The paddle means 15 is a thin wedge-shaped device constructed of a plastic, metallic or organic substance such as stainless steel or various stainless steel alloys which is impervious to gases and vapors which is capable of being formed around and containing a quantity of material which acts as a thermal insulator.

Suitable materials for constructing the vessel 11 of my thermal compressor and thermal regenerative means 10, include any type of plastic, metallic or organic substances which are impervious to gaseous and vaporous fluids and which act as thermal insulators or may be formed around such insulating material and are also susceptible of being formed into a definite enclosed volume. The closed conduit means 22, 23, 42 and 43 may be constructed from any type of plastic, metallic or organic substances which are impervious to gases and vapors, may act as or be formed around thermal insulators, and are susceptible of being drawn and formed into elongated, enclosed tubular shapes. The

valve means'20, 21, 40 and 41 likewise may be constructed from any type of plastic, metallic or organic substances which are impervious to gases and vapors, may act as or be formed around thermal insulators, and are susceptible of being formed in various shapes. The valve parts must be capable of being fitted together to form a gas-tight seal while at the same time moving on each other with minimal friction. The storage means of the pressure regenerative means 30 may be constructed from suitable materials more fully described in copending patent application Ser. No. 104,009, filed Jan. 5, 1971 provided that such' materials are also impervious to gases and vapors and are capable of acting or being made to act as thermal insulators. Preferable materials for constructing various parts are stainless steel, various stainless steel alloys, and ceramics.

The gas cycle gas cooling apparatus and process described above will preferably use air as the working gas. In such a case, it will take air from the atmosphere or confined space to be cooled, cool it and return it to the confined space to be cooled at a lower temperature than that in the confined space, thus performing as an air conditioner. It is obvious, however, that this apparatus and process in an atmosphere other than air will perform the same operation given a continuous supply of another gas such as helium or hydrogen. In addition, such gas supply could enter the gas cycle gas cooling apparatus at any temperature or pressure and still be cooled by the process described above.

It is also possible to use the gas cycle gas cooling apparatus as a closed system wherein the working gas is continuously recirculated. For example, where it is desired to cool a continuous stream of fluid such as chemicals, the fluid may be piped through the cooling volume of the CORE means or the cooled gas ejected from the CORE may be circulated about the warm fluid accepting the heat from the fluid. The warmed gas from the gas cycle gas cooling apparatus is then drawn back into the cooling volume of the CORE by a suitable means, such as an intermittent low temperature cooling means which reduces the pressure of the gas within the cooling volume. With the substitution of a low temperature cooling means for an atmospheric temperature cooling means, the gas cycle gas cooling apparatus will therefore operate without a continuous fresh gas source.

By way of illustration only, the minimum temperatures of the chilled gas in cooling volume 50 could range between 40 to 60 F for air and as low as 0 F if a gas other than air is used as the working gas. The preferred temperature for air is approximately 40 F. At temperatures lower than these minimums the moisture contained in said cooling volume 50 will begin to freeze. Moisture buildup within the CORE means, however, can be largely avoided by the use of a desiccant means on the inlet conduit 22. The cooling means should be at ambient temperature and effective to reduce the temperature of the gas in the cooling volume to between 80 to 120 F. The preferable operating temperature range of the heating means and the probable temperatures of the heating volume must be calculated from pressure, volume and temperature equations using the volume and temperature of the gas to be cooled, the operating temperature of cooling means and the desired temperature of the chilled gas but, generally, the temperature in the heating volume will range from 400 to 500 F and the temperature of the heating means will be at least 500 F.

The oscillation of the paddle means will be from 60 to 120 depending on the sizes of the other elements in the vessel,'but preferably between and 1 10.

The preferred cyclic frequency at which the gas cycle gas cooling apparatus will operate depends upon the size of the apparatus and the quantity of chilled gas required. Cyclic frequencies of up to about 500 cycles per minute are suitable for the cyclic gas cooling apparatus of my invention. Cyclic frequencies of less than about cycles per minute are suitable for the apparatus and process of my invention, however, due to practical limitations of size, are not highly desirable. The most suitable cyclic frequency for the apparatus and process of my invention is from about 100 to 500 cycles per minute. A preferred cyclic frequency is about 100 to 400 cycles per minute.

The cyclic gas cooling process of my invention, as more explicitly set forth previously, comprises sequentially: passing gas to be cooled into a cooling volume of a thermal compressor and thermal regenerative means while the previously cooled gas in said cooling volume is leaving said cooling volume to cool a confined space; stopping the outflow of the gas from said cooling volume to said confined space when the temperature in said cooling volume about reaches the level of the temperature in said confined space; passing gas from a heating volume of said thermal compressor and thermal regenerative means in sequence over heating means and heat regenerative means to said cooling volume; cooling the gas in said cooling volume; isolating said thermal compressor and thermal regenerative means from ambient atmosphere; returning gas stored in pressure regenerative means to said thermal compressor and thermal regenerative means resulting in an increase in pressure in said thermal compressor and thermal regenerative means while cooling said cooling volume thereby maintaining a constant temperature therein; isolating said thermal compressor and thermal regenerative means; passing a portion of gas from said cooling volume in sequence over said cooling means, said heat regenerative means and said heating means to said heating volume thereby increasing the pressure in said thermal compressor and thermal regenerative means; transferring a portion of gas from said thermal compressor and thermal regenerative means to a pressure regenerative means for storage thereby decreasing the pressure and temperature level of gas remaining in said cooling volume; isolating said pressure regenerative means from said thermal compressor and thermal regenerative means; passing said remaining gas from said cooling volume to a confined space thereby cooling said confined space; and repeating the cycle.

While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.

I claim:

1. A cyclic gas cooling process comprising sequentially:

passing gas to be cooled into a cooling volume of a thermal compressor and thermal regenerative means while the previously cooled gas in said cooling volume is leaving said cooling volume to cool a confined space;

stopping the outflow of the gas from said cooling volume to said confined space when the temperature in said cooling volume about reachesthe level of the temperature in said confined space; passing gas from a heating volume of said thermal compressor and thermal regenerative means in sequence over heating means and heat regenerative means to said cooling volume; cooling the gas in said cooling volume; isolating said thermal compressor and thermal regenerative means from ambient atmosphere;

returning gas stored in pressure regenerative means to said thermal compressor and thermal regenerative means resulting in an increase in pressure in said thermal compressor and thermal regenerative means while cooling said cooling volume thereby maintaining a constant temperature therein;

isolating said thermal compressor and thermal regenerative means;

passing a portion of gas from said cooling volume in sequence over said cooling means, said heat regenerative means and said heating means to said heating volume thereby increasing the pressure in said thermal compressor and thermal regenerative means;

transferring a portion of gas from said thermal compressor and thermal regenerative means to a pressure regenerative means for storage thereby decreasing the pressure and temperature level of gas remaining in said cooling volume;

isolating said pressure regenerative means from said thermal compressor and thermal regenerative means;

passing said remaining gas from said cooling volume to a confined space thereby cooling said confined space;

and repeating the cycle.

2. The process of claim 1 wherein said thermal compressor and thermal regenerative means is a single thermal compressor and thermal regenerative means.

3. The process of claim 1 wherein said thermal compressor and thermal regenerative means is a multiple thermal compressor and thermal regenerative means.

4. The process of claim 1 wherein said cooling means is an intermittent fluid cooled exchanger.

5. The process of claim 1 wherein said cooling means is an intermittent heat pipe.

6. The process of claim 1 wherein said cooling means comprises two, separated constantly operating cooling means located on both sides of and adjacent to said cooling volume.

7. The process of claim 1 wherein said gas to be cooled is introduced to said thermal compressor and thermal regenerative means from confined space to be cooled.

8. The process of claim 1 wherein said gas is air.

9. The process of claim 1 wherein said process is repeated at a frequency of about to 500 cycles per minute. t

10. he process of claim 1 wherein the temperature of the cooled gas is about 0 to 60F, the temperature of the heating means is greater than 400F, and the temperature of the cooling means is greater than or equal to the ambient temperature.

11. A gas cycle gas cooling apparatus comprising: vessel means for confining gas, heating means within said vessel means for heating said gas, cooling means withinsaid vessel means for cooling said gas, and heat regenerative means within said vessel means, said heat regenerative means being between said heating means and said cooling means, paddle means within said vessel rotatably mounted for oscillation between said heating means and said cooling means; said vessel means having conduit means containing valve means regulating flow of gas into said vessel means for cooling, said vessel means having conduit means containing valve means regulating flow of gas out of said vessel; and a pressure regenerative means having conduit means in communication with said vessel means and having valve means for isolating pressure regenerative means from said vessel means.

12. The apparatus of claim 11 wherein said vessel means is a single vessel means. 1

13. The apparatus of claim 11 wherein said vessel means is a multiple vessel means and said valve means regulating flow of gas into said vessel means are multiple valve means, and said valve means regulating flow of gas out of said vessel means are multiple valve means.

14. The apparatus of claim 11 wherein said valve means isolating pressure regenerative means from said vessel means is a single valve.

15. The apparatus of claim 11 wherein said cooling means is an intermittent fluid cooled exchanger.

16. The apparatus of claim 11 wherein said cooling means is an intermittent heat pipe.

17. The apparatus of claim 11 wherein said cooling means comprises two separated constantly operating cooling means located on opposite sides of a cooling volume and adjacent to said cooling volume.

UNITED STATES PATENT OFFICE CERTIFICATE 0F CORREQ'HN Patent No. 3,690,113 Dated September 12. 1972 Inventor(s) Raghunath G. Mokadam It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet [73] "Institute of Gas Technology, Chicago, Ill." should read American Gas Association,

Arlington, Va., a non-stock, non-profit corporation of Delaware Signed and sealed this 8th day of May 1973.-

(SEAL) Attest:

EDWARD M.FLETCHER,JR. 1 ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents FORM 1 0-1050 (10-69] USCOMM-DC 60376-P69 n us GOVERNMENT PRINTING OFFICE: I969 0-355-334. 

1. A cyclic gas cooling process comprising sequentially: passing gas to be cooled into a cooling volume of a thermal compressor and thermal regenerative means while the previously cooled gas in said cooling volume is leaving said cooling volume to cool a confined space; stopping the outflow of the gas from said cooling volume to said confined space when the temperature in said cooling volume about reaches the level of the temperature in said confined space; passing gas from a heating volume of said thermal compressoR and thermal regenerative means in sequence over heating means and heat regenerative means to said cooling volume; cooling the gas in said cooling volume; isolating said thermal compressor and thermal regenerative means from ambient atmosphere; returning gas stored in pressure regenerative means to said thermal compressor and thermal regenerative means resulting in an increase in pressure in said thermal compressor and thermal regenerative means while cooling said cooling volume thereby maintaining a constant temperature therein; isolating said thermal compressor and thermal regenerative means; passing a portion of gas from said cooling volume in sequence over said cooling means, said heat regenerative means and said heating means to said heating volume thereby increasing the pressure in said thermal compressor and thermal regenerative means; transferring a portion of gas from said thermal compressor and thermal regenerative means to a pressure regenerative means for storage thereby decreasing the pressure and temperature level of gas remaining in said cooling volume; isolating said pressure regenerative means from said thermal compressor and thermal regenerative means; passing said remaining gas from said cooling volume to a confined space thereby cooling said confined space; and repeating the cycle.
 2. The process of claim 1 wherein said thermal compressor and thermal regenerative means is a single thermal compressor and thermal regenerative means.
 3. The process of claim 1 wherein said thermal compressor and thermal regenerative means is a multiple thermal compressor and thermal regenerative means.
 4. The process of claim 1 wherein said cooling means is an intermittent fluid cooled exchanger.
 5. The process of claim 1 wherein said cooling means is an intermittent heat pipe.
 6. The process of claim 1 wherein said cooling means comprises two, separated constantly operating cooling means located on both sides of and adjacent to said cooling volume.
 7. The process of claim 1 wherein said gas to be cooled is introduced to said thermal compressor and thermal regenerative means from confined space to be cooled.
 8. The process of claim 1 wherein said gas is air.
 9. The process of claim 1 wherein said process is repeated at a frequency of about 100 to 500 cycles per minute.
 10. The process of claim 1 wherein the temperature of the cooled gas is about 0* to 60* F, the temperature of the heating means is greater than 400* F, and the temperature of the cooling means is greater than or equal to the ambient temperature.
 11. A gas cycle gas cooling apparatus comprising: vessel means for confining gas, heating means within said vessel means for heating said gas, cooling means within said vessel means for cooling said gas, and heat regenerative means within said vessel means, said heat regenerative means being between said heating means and said cooling means, paddle means within said vessel rotatably mounted for oscillation between said heating means and said cooling means; said vessel means having conduit means containing valve means regulating flow of gas into said vessel means for cooling, said vessel means having conduit means containing valve means regulating flow of gas out of said vessel; and a pressure regenerative means having conduit means in communication with said vessel means and having valve means for isolating pressure regenerative means from said vessel means.
 12. The apparatus of claim 11 wherein said vessel means is a single vessel means.
 13. The apparatus of claim 11 wherein said vessel means is a multiple vessel means and said valve means regulating flow of gas into said vessel means are multiple valve means, and said valve means regulating flow of gas out of said vessel means are multiple valve means.
 14. The apparatus of claim 11 wherein said valve means isolating pressure regenerative means from said vessel means is a single valve.
 15. The apparatus of claim 11 wherein said cooling means is an intermittent fluid cooled exchanger.
 16. The apparatus of claim 11 wherein said cooling means is an intermittent heat pipe.
 17. The apparatus of claim 11 wherein said cooling means comprises two separated constantly operating cooling means located on opposite sides of a cooling volume and adjacent to said cooling volume. 